Method and apparatus for treating products, including destroying insect life, disintegrating, cleaning, and separating



July 7. 1953 R. B. DODDS ET AL 2,644,7 0

METHOD AND APPARATUS FOR TREATING PRODUCTS, INCLUDING DESTROYING INSECTLIFE, DISINTEGRATING, CLEANING, AND sEPARATING Filed Oct. 4, 1948 1 3Sheets-Sheet l I 48 I 34 I 'NVENTORS R0$erf B. Dodds Arthur M HibbsJames D. Napier ATTOR Y5 July 7. 1953 R. B. nouns ET AL 2,644,7 0

METHOD AND APPARATUS FOR TREATING PRODUCTS, INCLUDING DESTROYING INSECTLIFE, DISINTEGRATING, CLEANING, AND SEPARATING Filed Oct. 4, 1948 3Sheets-Sheet 2 4 6\ 8 I 24 J a: 22

I? 54 26 38 0 I I 1| f 3 34 34 I 5 52 f F I INVENTORS Robert .D CZd' v 3I ATTORN Ys y 7. 1953 R. B. DODDS ET AL 2,644,740

METHOD AND APPARATUS FOR TREATING PRODUCTS, INCLUDING DESTROYING RATING,CLEANING, AND SEPARATING INSECT LIFE DISINTEG 4, 1948 3 Sheets-Sheet 3Filed Oct.

INVENTORS Robert B. Dada .HrihurJl/Tfiibbs Jdmes be) I Lav/10g ATTOR EYSD. Nap' Patented July 7, 1953 PRODUCTS, INCLUDING DESTROYING IN- SECTLIFE, DISINTEGRATING, CLEANING,

AND SEPARATIN G Robert B. Dodds, Woodbridge, Arthur N. Hibbs, MountCarmel, and James D. Napier, Hamden, Conn., assignors to The Safety CarHeating and Lighting Company,

. Delaware Inc., a corporation of Application October 4, 1948, SerialNo. 52,756

14 Claims.

This invention relates to centrifugal apparatus and methods ofprocessing flowable materials.

More particularly, this invention relates to the separation of materialsby centrifugal action; andthis separation may be accompanied by animpacting action which is effective to cause comminution of certainproducts or' to knock loose constituent'parts, and with food productsthe impacting action, may be efiective to destroy insect life.

Anobject of this invention is to provide an improved method andapparatus for treating products to remove certain materials,constituents or parts therefrom. A further object is to provide a methodand apparatus for subjecting a product to a preliminary treatment, suchas,

the destruction of insect life therein or the knocking loose of productparticles; and, then to follow this preliminary treatment by aseparating action wherein the major portion of a certain constituent orcertain constituents, or particles of a particular size, are removedfrom the product. A further object is to provide an improved manner oftreatment of a product, such as, bran or shorts or buckwheat hulls, toremove endosperm particles or the like therefrom. A further object is toprovide an improved method and apparatus for whizzing cereals such aswheat and com.

A further object is to provide for the above with the additional featurethat any insect life H in the product is destroyed during the operation.A further object is to provide apparatus for carrying out the abovewhich is simple and sturdy in construction, economical to manufacture,operate "and maintain, and extremely reliable and efiicient in use. Afurther object is to provide for the carrying on of the'ab'oveoperations in a continuous' manner so that a thorough and uniformtreatment is provided. These and other objects will be in part obviousand in part pointed out below.

The invention accordingly consists in the features of construction,combinations of elements, arrangements of parts, and in the severalsteps and relation and order of each of the same to one or more of theothers, all as will be illustratively described herein, and the scope ofthe application of which will be indicated in the following claims.

In the drawings:

Figure 1 is a view partially in section showing one embodiment of theinvention; and,

Figures 2 and 3 are views showing another embodiment of the invention.

The present inventionrelates to the invention 4 covered by U. S. PatentNo. 2,339,737, and also to the invention disclosed in the co-pendingapplication pf Robert B. Dodds, Serial No. 781,130, filed October 21,1947, now Patent No. 2,529,679. In Patent No. 2,339,737 there isdisclosed a method and apparatus for treating bulkproducts for thedestruction of all insect life therein. A portion of the apparatus ofthe'illustrative embodiments of ,the present invention is the same astheapparatus disclosedv in this patent.

Patent No. 2,529,679 an arrangement is disclosed whereby bulk productsmay be treated byapparatus such as that of Patent No. 2,339,737 so as todislodge certain constituents of the product, and then the product issubjected to an aspiratingaction to'separate out certain of theconstituents H The present invention is directed primarily to theseparation of certain constituents from others by centrifugal action andparticularly by providing an arrangement which produces a, whirlingaction in a perforated annular Wall with the result that certainconstituent particles pass through the perforations into an outer zone,whereas the remainder of the particles are confined within theperforated wall. The rotation of theproduct is obtained by passing astream of the product through a rotor with an accompany ing "stream ofair so as to produce a cyclone action. The rotor construction and itsspeed of rotation may be such as to break or knock loose constituentparticles, thus to obtain somewhat of a milling or comminuting actionand with appropriate products the rotor may'produce' an impa'c'tingaction sufficient to kill any insect life which is present. l

' Y In the illustrative embodiments of the present that the effect ofthe rotoris merely to produce a rapidly rotating stream of the productand the accompanying air.

The action "at thegrotor is followedby theseparating action referred toabove with ther size from others.

in suspension; the cycloneeffect tends to :throw the product particlesfrom the air against the perforated wall, but the air continues to whirlwith the result that the product particles are carried with it and slideand tumble around the perforated wall. The major portion of the airpasses through the perforations in the wall. and the smaller sizedparticles pass through the perforations by the combined action of thecentrifugal forces resulting from the rotary movement and the flow ofthe air.

In accordance with certain of the broader aspects of the presentinvention products such I as wheat or corn may be given a preliminarytreatment by water, and the water may then be removed by passing thestream through a centrifugal machine with the air and water passingthrough'the perforations in a screen and with the wheat or corn passingdown the screen. In accordance with certain other broad aspects of theinvention the insect-destroying feature referred'to above isunimportant,v and therefore, the impacting action may be eliminated orit may be only of such a nature as to produce the desired knocking looseor breaking up of the.

product; thus under some circumstances the apparatus may be mainly forseparating certain constituents or particles smaller than a certain 7With the separating arrangement of the present invention the amount ofthe product which is separated from the main stream is determined mainlyby the size of the openings in the perforated wall, but it is alsodetermined to some extent by the amount of air which accompanies thestream of the product. Thus, for each specific application of thepresent invention the various features of construction-and operation ofthe apparatus are such as will give the bestresults. Many of the factorswhich determine the specific structure and mode of operation for thevarious applications are discussed in detail herein whereas more obviousones are not discussed.

Referring particularly to Figure '1 of the drawings there is shown atthe top an electric motor 2 mounted on the top of a casing structure 4and having a shaft 6 which projects through an opening 8 in the top ofthe casing structure and has keyed at its lower end a hub In of a .rotor12. This motor and casing and. rotor structure is the .same as thecorresponding structure in the above-identified patent. The casingstructure 4 has a downwardly extending peripheral'flange portion orshell I 4 :and at the two sides of the motor there are product inletspouts I6. Rotor 1.2 is formed by a bottom plate l8 which is secured tohub l0 by a plurality of'studs and nuts 20, and this plate carries adouble row of cylindrical impaotors 22 which in turn carry an upperannular .plate 24.

The lower edge ofshell l4 has a groove 28 which .is substantially filledby a rubber ring and pressing against this rubber ring is the top flange28 of a hopper structure 30 which includes a cylindricalupper section 32and a non-symmetrical hopper 34 which has a product outlet spout .36 atthe left. The hopper structure is supported by a plurality of swingingbolt and nut assemblies 4 38 which are attached to shell l4 and providea removable supporting means for the hopper structure. Positioned on theinside of top flange 28 at theiloweriedge thereof and 'welddthereto 1 isa ring 40' which provides a supporting ledge for a similar ring 42 whichis the top flange on a perforated hopper 44. Hopper 44 is formed by anupper annular wall 46 of perforated sheet 7 metal and a lower annularwall 48 which is of imperforate sheet metal. These walls are bothfrusto-conicaland they are brazed together to I form a continuousfrusto-conical wall which is brazed at the top to ring 42. At the bottomwall 48 has a collar 50 which fits within a chute 52 whcihprojectsdownwardly through the wall of hopper 34. Thus the perforated hopper 44is removably supported at its top and bottom and it may be removed andreplaced readily by merely dropping the hopper structure 30 and theconnecting chutes.

. With this arrangement a product such .asbran passes into/the top. ofthecasingstructure 4 'through the inlet chutes it and it is passed.through the rotor with an; accompanying stream of air inthe mannerdescribed indetail in Patent No. 2,339,737. zDuring zthe passage throughthe rotor the stream of product isspread out and its rate of movementrisincreased so that it is in a fairly thin stream with the result that theproduct particles are thoroughly treated-.;.The'

action is such that .al. insect life which, may be present is destroyed,and at' thesame time. particlesv of endosperm'ar-e knocked loose fromthe bran particles. The product is discharged ata rapid rate at theperiphery of the rotor andis directed downwardly by shell J4 so thatittends to cause a cyclone or vortex within the perforated hopper 44.Chute 52 being connected in the mill stream, is restrictedso that air isnot discharged through it in any substantial amount, whereas chute isopen in the sense that .air vmay dischargethrongh it. Accordingly theair which .accompanies the product atthe periphery of the rotor mndstopassthrough the perforations in wall 45. vAt the same-time the rotarymovement of the air and the product tends to throw the product particlesfrom the air against wall. 46 and the product particles slide and tumblearound this wall at a rapid rate. The "combined action of centrifugalforces and the flow of air through the perforations iii-wall 46 causesthe particles of endosperm to pass through these perforations Whilethebran-particles :are confined by wall 45.- fIhusthaendosper-m isseparated vout and is discharged atfiii, whereas the bran-passesdownwardlythrough chute 52.

The action within ethe ro-tcr "is such that the bran'particles are notreduced to any material extent and wall .46 has perforationsof such sizeas to permit the passage of the endospermparticles which are in thisembodiment in the nature .of dust. natural air pressure-of rotor I2 whenoperating at 35-90 R. .P. ,M. is sufficient to produce the desired airflow. r In one installation the perforations wall 46 were .045 inch inminor dimension, andin another instance this dimension was :07-3 inch.Under some circumstances wire mesh has beensused.

' The apparatus of Figure 1 has proved satisfactory for separatingendosperm from bran and from shor.ts,.and also for separating endospermfrom buckwheat hullsit being understood that appropriate perforationsizes are used to remove particles of the desired. sizes. 7

In Figure 2 there'is shown on a reduced scale '5 an arrangementsimilarf'to that of Figure 1 with the addition 'of'means to increasethe, air flow through the separating zone. Accordingly fixed to thebottom of rotor I2 is a set ofair'impeller blades or vanes=54 andcentrally positioned within chute 52 is an air inlet tube'5B. Tube56'c'arries at its upper end afrusto-conicalbaffle 58 which isstationary and which forms with'the bottom sof rotor [2 an annularradial passageway for air.

Thus during the rotation of the rotor air is drawn in through tube 56and passes upwardly 'and is directed radially outwardly by vanes 54.This stream of air is added to the. stream of air'which accompanies theproduct through the rotor and isdischarged through the perforations inwall "46 and outlet 36. The-effect of this added air is to increasematerially'the tendency for product par ticles to pass through theperforations and therefore a very thorough separation is obtained eventhough a very substantial portion of the stream is being separated offthrough the perforations.

'Figure 3 is similar 'toFigure 2 but shows a form of theinvention'wherein additional space is provided for the discharge of .theair and the separated particles; In Figure 3 a'ring 60"replaces flange28 and carries a cylindrical shell formed by an annular top .:wall 62and .a' downwardly extending cylindrical wall 64. This shell has ahopper bottom 66 with .a productoutlet opening at the bottom. Ring 60has a ledge portion which supports a ring 68' of a perforated hopperstructure '10. *iThe perforated hopper structure includes an uppercylindrical perforated wall portion 12, a frusto-aconical perforatedwall portion 14, and an imperforate frusto-econical wall portion 16, allbrazed together to form a rigid structure. The operation in theembodiment of Figure 3 is similar to that of the other embodimentsexcept that a larger discharge Zone is provided around the perforatedhopper structure and the upper portion of the perforated wall is,cylindrical rather than frusto-conical. Thus for certain conditions ofoperation improved results are obtained with this construction.

As indicated above the apparatus herein disclosed is adaptable foruse-in whizzing grain and for other operations wherein a thorough andrapid separation is required. -When no milling action is necessary ordesired the rotor structure may be modified and the rate of rotation maybe reduced. Similarly when no insect destruction is necessary thestructure and operation may be modified accordingly. The structure isadmirably suited for carrying on reducing operations in the milling ofwheat, in the processing of corn and in the milling of granular productsof various kinds. For some operations impactors 22 are replaced byblades, and under some circumstances hub I0 is of reduced thickness soas to permit a freer flow of the product, outwardly toward theimpactors.

As many possible embodiments may be made of the mechanical features ofthe above invention and as the art herein described might be varied ingsaid rotor and defining at the periphery of the rotor a discharge zonehaving an impact surface against which the rotating stream of theproduct passes and means forming a pair of separation hoppers beneathsaid zone and connected 2. Apparatus as described in claim [whereinsaidseparating wall is a frusto-conical wall extending downwardly andradially inwardly.

3. Apparatus as described in claim 1 wherein said separating wall isformed by a cylindrical wall portion having at its lower edge afrustoconicalwall portion which extends downwardly andradially'inwardly. Y I

4. Apparatus as described in claim 1 which includes air-impelling meansmounted on said rotor to direct a stream of air into the stream of theproduct as the product passes from said rotor.

5. Apparatus as described in claim 4 wherein said impeller means is inthe form of a plurality of vanes mounted on the bottom offsaid rotor,

and an air supplystructure mounted beneath said rotor to pass air tosaidyanes and comprising an annular'bafiie member and an air conduitconnected to the center of said bafii'e member.

6. Apparatus as described in claim 5 wherein said separation hoppers arein the'form of inne'r and outer hopper structures, said outer hopper ofsaid particles .exert substantial centrifugal force, said casingincluding a wall portion surrounding said rotor against which all ofsaid particles are flung, said rotor accordingly imparting to the streamof particles a high velocity swirling or cyclonic action, a hoppersecured to the bottom of said casing in a position to receive saidcyclonic stream which'accordingly swirls about and against the wall ofsaid hopper together with the entrained air, said hopper having aplurality of small holes formed therein of a size large enough to passsmall stream particles and the air, but too small to pass thelargerparti cles, a discharge outlet for said hopper adapted to beconnected in the mill stream, and means forming an expansion chamberconnectedlto said casing and surroundig said hopper to receive the smallparticles and the air passing through said holes.

8. Apparatus according to claim '7, wherein the wall of said 'hopper'isof frustoconical form and extends downwardly and radially inwardly ofsaid casing.

9. Apparatus according to claim '7, wherein the wall of said hopper isof frustoconical form and extends downwardly and radially inwardly ofsaid casing, said holes being formed in the upper portion of said hopperwall only. i -10. In apparatus for treating a bulk product,

the combination of, a rotor defining an annular treatment zone throughwhich the product flows to impart rotary movement thereto; a downward-Jyextending casing constructionsurrounding said --rotor and defining atthe periphery of the rotor adischarge zone having an impact surfaceagainst .which the rotating stream of the product passes,

rotating annular stream of the product passes along said separating wallwith the smaller particles passing through said openings and with thelarger particles passing downwardly along said wall.

.11. ,Apparatus according to claim -10, wherein the separating wallincludes an upper cylindrical portion, and a lower frustoconicalportion.

12. In apparatus for treating a bulk product, the combination of, acasing, a high velocity rotor rotatably mounted in said casing, saidrotor having mounted thereon a plurality of upwardly extending productparticle engaging members adapted when the product is fed-to said rotorto engage the product'particles together with any foreign particles inthe product stream such as forms of insect life, whereby all of saidparticles exert substantial centrifugal force, said casing including adownwardly and outwardly extending imperforate wall portion surroundingsaid rotor against which all of said particles arefiung, .said rotoraccordingly imparting to the stream of particles a high velocityswirling Or cyclonic actionhaving a downwardly extending component, ahopper secured to the bottom of said casing in a position to receivesaid cyclonic stream which accordingly swirls about and against the wallof said hopper together with the entrained air, said hopper having aplurality of small holes formed therein of a size large enough to passsmall stream particles and the air, but too small to pass the largerparticles, a discharge outlet for said hopper adapted toocbe.connectedin the mill stream, and means forming an expansion chamberconnected to said'casing and surrounding said hopper to receive thesmall particles and the air passing through said holes.

13. Apparatus according to-claim '12, wherein the wall of said hopperunderlies all portions .of said rotor and includes a' frustoconicalportion which extends downwardly and radially inwardly ofsaidcasing.

114. In the art of treating a cereal product such as wheat forthedestruction of insect life and'for the separation .of constituentparts therefrom, the steps of, passing the stream of the -product withan accompanying stream of air substantially horizontally through atreatment zone by subjecting the product particles to high velocitycentrifugal action, subjecting the product particles to animpac'tingaction during their passage through saidtreatment zone of sufficientmagnitude to destroy and comminute insect life'therein, dis-' chargingtheproductzstream with the airin a substantially flat thin horizontalwhirling high velocity stream, deflecting the stream downwardly whilesubstantially maintaining its angular velocity, converging'said streamduring its downwardmovement, subjecting the'stream of product to ascreening action and at the same time expanding: the air laterally ofthe converging path of movement of the stream whereby there is withdrawnfrom the downwardly moving stream small constituent particles thereofin-" cluding the comminuted insect life together with a substantialamount of air, discharging said small particles and comminuted insectlife downwardly; and directing the larger particles of the -=streamdownwardly along a predetermined path References cited .inthe fileofthis patent UNITED STATES PATENTS Date .Number Name 2,339,737 HulseJan. 18, 1944 2,391,929 Smith Jan. 1,1945

14. IN THE ART OF TREATING A CEREAL PRODUCT SUCH AS WHEAT FOR THEDESTRUCTION OF INSECT LIFE AND FOR THE SEPARATION OF CONSTITUENT PARTSTHEREFROM, THE SEPTS OF, PASSING THE STREAM OF THE PRODUCT WITH ANACCOMPANYING STREAM OF AIR SUBSTANTIALLY HORIZONTALLY THROUGH ATREATMENT ZONE BY SUBJECTING THE PRODUCT PARTICLES TO HIGH VELOCITYCENTRIFUGAL ACTION, SUBJECTING THE PRODUCT PARTICLES TO AN IMPACTINGACTION DURING THEIR PASSAGE THROUGH SAID TREATMENT ZONE OF SUFFICIENTMAGNITUDE TO DESTROY AND COMMINUTE INSECT LIFE THEREIN, DISCHARGING THEPRODUCT STREAM WITH THE AIR IN A SUBSTANTIALLY FLAT THIN HORIZONTALWHIRLING HIGH VELOCITY STREAM, DEFLECTING THE STREAM DOWNWARDLY WHILESUBSTANTIALLY MAINTAINING ITS ANGULAR VELOCITY, CONVERGING SAID STREAMDURING ITS DOWNWARD MOVEMENT, SUBJECTING THE STREAM OF PRODUCT TO ASCREENING ACTION AND AT THE SAME TIME EXPANDING THE AIR LATERALLY OF THECOVERGING PATH OF MOVEMENT OF THE STREAM WHEREBY THERE IS WITHDRAWN FROMTHE DOWNWARDLY MOVING STREAM SMALL CONSTITUENT PARTICLES THEREOFINCLUDING THE COMMINUTED INSERT LIFE TOGETHER WITH A SUBSTANTIAL AMOUNTOF AIR, DISCHARGING SAID